Abstract: A supernumerary robotic limb (SRL) system can include a plurality of rigid links, a joint that connects one rigid link to another rigid link in the plurality of rigid arms, and two variable stiffness actuators (VSAs) configured to drive the plurality of rigid links in order to complete at least one task. The VSAs can exhibit infinite rotation and infinite stiffness. The VSAs can include an output link. Additionally, the VSAs can include a set of elastic elements mounted on the output link. The VSAs can include an input link configured to provide kinetic energy for the output link. The VSAs can include a dynamic chassis configured to connect with the input link. Additionally, the VSAs can include a stiffness adjustor included in the dynamic chassis and configured to adjust an elastic transmission between at least one elastic element of the set of elastic elements and the output link.

Abstract: The present disclosure is related to systems and/or methods for energy storage in desert environments. Various embodiments described herein include a system for subterranean energy storage. The system can comprise a subterranean flexible storage vessel coupled to a heat exchanger. The heat exchanger can be configured to supply a cooled compressed gas stream to the subterranean flexible storage vessel. Further, the subterranean flexible storage vessel can be at least partially surrounded by sand. Additionally, the system can comprise a turbine generator coupled to the subterranean flexible storage vessel. The subterranean flexible storage vessel can be configured to supply a pressurized gas stream that is heated by the sand to the turbine generator.

Abstract: A wellbore assembly includes a wellbore string disposed within a wellbore and a cement retainer coupled to a downhole end of the wellbore string. The cement retainer includes a housing, a packer, a valve, and a sleeve. The housing includes one or more fluid ports extending from an interior surface of the housing to the annulus. The housing defines a first fluid pathway extending from within the wellbore string to within the housing. The sleeve is movable between a first position, in which the sleeve blocks the one or more fluid ports, and a second position in which the sleeve exposes the one or more fluid ports to open a second fluid pathway extending from the annulus, through the one or more fluid ports, to the first fluid pathway. Opening the second fluid pathway allows mixing of a first fluid with a second fluid in the cement retainer.

Abstract: The present disclosure relates to a method of making a zeolite. The method includes mixing an aluminum nitrate with an aqueous solution of NaOH to form a first mixture followed by mixing silica gel with the first mixture to form a second mixture. The second mixture is heated with microwave irradiation to form a first sample. The method further includes washing, drying, and ion exchanging the first sample with ammonium nitrate to form a second sample. The method includes calcining the second sample to form the zeolite, wherein the method does not use a seed or a structural directing agent.

Abstract: Aspects relate to a compact material analyzer including a light source, a detector, and a module including a first optical window on a first side of the module, a second optical window on a second side of the module opposite the first side, and a light modulator. The light source produces input light at a high power that is passed through the first optical window to the light modulator. The light modulator is configured to attenuate the input light, produce modulated light based on the input light, and direct the modulated light through the second optical window to the sample. The modulated light produced by the light modulator is at a lower power safe for the sample. The detector is configured to receive output light from the sample produced from interaction with the modulated light through the second optical window and to detect a spectrum of the output light.

Abstract: Compositions and methods for increasing a stimulated reservoir volume in a hydrocarbon-bearing formation in fluid communication with a wellbore, one method including drilling a plurality of lateral extensions at varying depths in the formation extending from a vertical wellbore using slickwater hydraulic fracturing fluid, the slickwater hydraulic fracturing fluid comprising at least one friction reducer; and injecting an exothermic reaction component into the plurality of lateral extensions to create a plurality of fractures extending outwardly from and between the plurality of lateral extensions to create a multilateral fracture network.

Abstract: A wellbore assembly includes a cable and a wellbore tool. The wellbore tool is coupled to the downhole end of the cable. The wellbore tool includes a housing, one or more sensors, a packer, and a controller. The one or more sensors are coupled to the housing or to the cable or both. The sensors detect one or more parameters of the wellbore tool or the cable or both. The controller is coupled to the housing. The controller is electrically coupled to one or more sensors and is operationally coupled to the packer. The controller determines, with the wellbore tool parted from the cable and based on information received from the one or more sensors, an indication of the wellbore tool in free fall. The controller activates, based on the determination, the packer to expand the packer and set the wellbore tool on a wall of the wellbore.

Abstract: Provided are techniques for encrypting a virtual disk of a virtual computing instance (VCI) while the VCI is online and still running using a mirror driver. In certain aspects a mirror driver is a filter running in an I/O stack used for accessing a virtual disk, such that the mirror driver receives I/Os destined to the virtual disk and mirrors those I/Os to the virtual disk and one or more additional virtual disks. The mirror driver begins copying data from an unencrypted source virtual disk to a destination virtual disk, and the data is encrypted as it is stored in the destination virtual disk, while the VCI is still online. During the copying, as new writes are issued to the unencrypted source virtual disk from the VCI, the mirror driver mirrors the writes to both the unencrypted source virtual disk and the destination virtual disk.

Abstract: Compositions and methods for increasing a stimulated reservoir volume in a hydrocarbon-bearing formation in fluid communication with a wellbore, one method including drilling a plurality of lateral extensions at varying depths in the formation extending from a vertical wellbore using slickwater hydraulic fracturing fluid, the slickwater hydraulic fracturing fluid comprising at least one friction reducer; and injecting an exothermic reaction component into the plurality of lateral extensions to create a plurality of fractures extending outwardly from and between the plurality of lateral extensions to create a multilateral fracture network.

Abstract: A method of determining a fouling location of a shell and tube heat exchanger is provided. Under the method, a simulation model of the heat exchanger is partitioned into multiple segments. Each segment corresponds to a different one of multiple operating scenarios of the heat exchanger. For each operating scenario, temperature data and pressure drop data are generated from the simulation model of the heat exchanger. The fouling location of the heat exchanger corresponds to a respective segment in each of the multiple operating scenarios. The temperature data and the pressure drop data are classified based on the multiple segments of the simulation model by inputting the temperature data and the pressure drop data to one or more machine learning classification algorithms. The fouling location and a value of accumulated fouling at the fouling location are determined based on the classified temperature data and the classified pressure drop data.

Abstract: A whipstock assembly including a main body defining an axial direction extending through the main body, a circumferential direction, and a radial direction transverse to the axial direction, and a ramp body pivotally coupled to the main body, the ramp body defining a ramp surface that is oriented transverse to the radial direction, and where the ramp body is movable between a retracted position and an extended position, where the ramp surface is further from the main body in the axial direction in the extended position as compared to the retracted position and the ramp body is rotatable with respect to the main body about the circumferential direction.

Abstract: A DC-DC conversion scheme is described and includes a main inductor connected in series with a first circuit leg and a second circuit leg, the first and second circuit legs being arranged in parallel with one another. Each circuit leg includes a first inductor, a second inductor and a third inductor arranged in series with a primary switch, a first switched ground connection being connected to a location between the first and second inductors, and a second switched ground connection being connected to a location between the second and third inductors. The first, second and third inductors of the first and second legs are wound upon a common core.

Abstract: An electrical conversion apparatus for use in current shaping comprising at least two capacitors connected in series between first and second lines, a first diode connected in parallel across the first capacitor, a second diode connected in parallel across the second capacitor, and a constant current device connected in series with the first and second capacitors.

Abstract: Techniques for removing a tubular from a wellbore include running a downhole tool on a downhole conveyance into a wellbore formed from a terranean surface into a subterranean formation; activating a piston sub-assembly to repeatedly move pistons to contact a portion of a casing installed in the wellbore to at least de-bond a cement layer installed between the portion of the casing and the subterranean formation from the portion of the casing; activating a cutting sub-assembly to move a cutting blade to cut through the portion of the casing adjacent the de-bonded portion of the cement layer; activating a hanger sub-assembly to move a set of slips into contacting engagement with the cut portion of the casing; and running the downhole tool on the downhole conveyance out of the wellbore with the cut portion of the casing engaged with the set of slips.

Abstract: A wellbore assembly includes a cable and a wellbore tool. The wellbore tool is coupled to the downhole end of the cable. The wellbore tool includes a housing, one or more sensors, a packer, and a controller. The one or more sensors are coupled to the housing or to the cable or both. The sensors detect one or more parameters of the wellbore tool or the cable or both. The controller is coupled to the housing. The controller is electrically coupled to one or more sensors and is operationally coupled to the packer. The controller determines, with the wellbore tool parted from the cable and based on information received from the one or more sensors, an indication of the wellbore tool in free fall. The controller activates, based on the determination, the packer to expand the packer and set the wellbore tool on a wall of the wellbore.

Abstract: A multistage plunger lift system includes an upper production tubing segment positioned in a wellbore uphole of a lower production tubing segment, with the upper segment having a greater diameter than the lower segment. A lower travelling plunger and an upper traveling plunger are sized and configured to fit and travel within the lower segment and the upper segment, respectively. A plunger lift tool is positioned in the upper segment between the upper plunger and the lower plunger, and includes within its main body a fluid passageway with a one-way valve. A plunger receptacle sleeve at the bottom end of the lift tool receives the lower plunger and includes one or more vents configured to allow fluids to flow around the lower plunger when the lower plunger is received within the plunger receptacle sleeve.

Abstract: A method of fixating CO2 to form a substituted oxazolidinone is described. The method includes mixing a nickel-based metal-organic framework (Ni-MOF) catalyst of formula [Ni3(BTC)2(H2O)3]·(DMF)3(H2O)3, a cocatalyst, an aromatic amine, and at least one epoxide to form a reaction mixture, and further contacting the reaction mixture with a gas stream containing carbon dioxide to react the carbon dioxide in the gas stream with the epoxide and the aromatic amine to form a substituted oxazolidinone mixture. The method further includes adding a polar protic solvent to the substituted oxazolidinone mixture, centrifuging, and filtering to produce a recovered Ni-MOF; and further washing the recovered Ni-MOF with an organochloride solvent and drying for at least 5 hours to produce a recycled Ni-MOF.

Abstract: A control arrangement that includes an inductor of small inductance and having an input side and an output side, the input side being connected to an input line connected, in use, to an output from a power supply, and the output side being connected to an output line connected, in use, to a load. A switched capacitor arrangement is located at the input side of the inductor, the switched capacitor arrangement being arranged such that an average voltage on the input line is maintained above a predetermined level during use of the control arrangement.

Abstract: A smart jarring system for freeing stuck equipment downhole is disclosed. The smart jarring system comprises a set of jars, at least one laser source and at least one laser receiver that corresponds to the at least one laser source. The laser receiver intercepts a laser beam that is emitted from the laser source. This interception helps determine when the set of jars fired and in which direction the set of jars fired. The smart jarring system further comprises one or more sensors selected from the group consisting of vibration sensors, temperature sensors, and torque/tensile sensors. These sensors are configured to diagnose downhole conditions and help free the stuck equipment downhole.

Abstract: A computer-implemented method for managing data quality is provided. The method comprising determining, by a rule engine, a number of critical data points in a number of different software modules. A classifier is identified based on a data type of the critical data points, and the classifier is bound to the critical data points. The classifier scans the critical data points for anomality to verify an ability to correctly process the critical data points. A data quality report is generated based on the scan and displayed to an end user in a graphical user interface.